Improvements in the drive system for bicycles

ABSTRACT

The invention relates to improvements in the drive system of bicycles, according to which the pedal axle ( 5 ) of the bicycle of application is located at a distance between 185-300 mm behind the vertical of the seat ( 2 ), whereas the pedals ( 4 ) are incorporated on connecting rods ( 7 ) of 250-360 mm in length.

FIELD OF THE ART

The object of the present invention relates to the structuralconfiguration of bicycles and specifically to the type in which thepedal axle is arranged in a position behind the vertical of the seat,proposing a drive system to be applied in this type of bicycle withfeatures that allow performing an exercise that is equivalent to thatwhich is developed when running.

STATE OF THE ART

Practicing physical exercise on a sport level entails risks ofexperiencing bodily injuries due to repetitive and intense strainingthat the muscles and joints of the body must withstand.

In order to try to minimize as much as possible the occurrence ofinjuries due to excessive work according to the type of exercise that ispracticed and to maximize the degree of performance, generally trainingsessions in a gym by means of different apparatuses are usually combinedwith specific training sessions for the corresponding discipline.

Training sessions in a gym consist of using different types ofapparatuses which allow exercising different groups of muscles andjoints to reinforce the areas of the body that are involved in physicaleffort for the purpose of preventing the occurrence of certain injuries.

One of the sports in which injuries usually occur is running, anactivity that is considered to be a “high impact” sport. In thisdiscipline, the most common injuries are knee pain (commonly referred toas “runner's knee”), shin pains, pulled muscles, twisted ankles,iliotibial band syndrome, the inflammation of the Achilles tendon orstress fractures.

Athletes who practice this discipline generally have training sessionsin a gym on a treadmill, however runners with the “runner's knee”injury, which is caused by a misalignment of the knee joint which doesnot allow absorbing the impact produced in the stepping when running,have difficulties in this type of training, so they usually combine itwith the use of a bicycle to achieve better performance. However,exercising on conventional bicycles does not activate the same groups ofmuscles as those that are activated when running, so training for thiseffect in such conditions is deficient.

Bicycles have recently been developed with a drive system characterizedby the pedal axle being arranged in a position that is shifted behindthe vertical of the seat. These types of bicycles have been designed forthe purpose of reaching maximum user performance due to the postureadopted on the bicycle. However, the embodiments of bicycles of thistype do not provide exercise conditions equivalent to those of theactivity when running.

OBJECT OF THE INVENTION

According to the invention a drive system for bicycles is proposed, theembodiment of which is provided with constructive features making thissystem particularly advantageous compared to the conventional solutionsof the same application.

The proposed drive system is of the type which places the pedal axle ina position behind the vertical of the seat of the bicycle, this positionof the pedal axle being determined according to the invention at acertain distance from the vertical of the seat, furthermoreincorporating the pedals by means of connecting rods of greater lengththan conventional ones, such that it achieves an arrangement with whichthe user of the bicycle adopts a position which allows exercising themuscles and joints in the same conditions as when running.

The proposed drive system has been developed from a comparative testbetween the efforts affecting a user who runs and the efforts affectinga user who exercises on a bicycle provided with said proposed drivesystem.

According to the system of the invention, the pedal axle is arranged ata distance between 185-300 mm behind the vertical of the seat of thebicycle, arranging the pedals on connecting rods of a length between 250and 360 mm, which is essentially greater than that of the connectingrods of pedals in conventional bicycles.

With this arrangement of the system of the invention, the user of thebicycle adopts a posture so that the angle formed by the knees inmaximum bending is 44°, whereas in maximum extension the angle at theknees is 155°, while the angle of maximum bending at the hip is 62° andin the position of maximum extension said angle is 145°.

It is thus achieved that when using the bicycle, the same muscles andjoints as those exercised when running are exercised, therefore solvingthe training drawbacks for people who have problems with injuriesaffecting the impact of stepping on the surface of the ground.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic depiction of the position of a user on aconventional stationary bicycle, in the situation of maximum extensionof the body.

FIG. 2 is a schematic depiction of the position of the user on the samebicycle as above, in the arrangement of maximum bending of the body.

FIG. 3 is a side view of a stationary bicycle provided with the drivesystem of the invention.

FIG. 4 is a plan view of the bicycle of the previous figure.

FIG. 5 is a schematic depiction of the position of a user on the bicyclewith the drive system of the invention, in the situation of maximumextension of the body.

FIG. 6 is a representation of the position of the user on the samebicycle of the previous figure, in the situation of maximum bending ofthe body.

DETAILED DESCRIPTION OF THE INVENTION

The present invention proposes a drive system for bicycles, with whichthe user performs a body work that is equivalent to the work which isdeveloped when running.

The proposed drive system can be applied both in stationary bicycles andin conventional bicycles with wheels, provided with a handlebar (1) anda seat (2) that can have different configurations and they can beheight-adjustable in order to be adapted to different users (3), thefunctional arrangement including a drive system operated by pedals (4).

The system of the invention is particularly provided for bicycles thepedal axle (5) of which is arranged in a position behind the vertical ofthe seat (2) of the corresponding bicycle.

In a bicycle with a conventional arrangement, such as the one shown inFIGS. 1 and 2, the pedal axle (5) of the operating system is located infront of the vertical of the seat (2), at a distance between 240 and 260mm from said vertical, whereas the pedals (4) are incorporated withrespect to the pedal axle (5) by means of connecting rods (6) of about200 mm in length.

This configuration of conventional bicycles means that the user (3)adopts on such bicycles a posture such that, according to the depictionof FIG. 1, said user acquires an angle (α) of 135° at the knee of theextended leg in the position of maximum extension of the body, whereasthe angle (β)between said extended leg and the body of the user (3) is104°.

In the same manner, in the situation of maximum bending, such as the onedepicted in FIG. 2, the angle (α′) that is acquired at the knee of thebent leg is 84°, whereas the angle (β′) between said bent leg and thebody of the user (3) is 65°.

According to the system of the invention, the pedal axle (5) is arrangedat a distance between 185 and 300 mm behind the vertical of the seat (2)of the bicycle, in accordance with the arrangement depicted in FIG. 3,while the pedals (4) are incorporated in the assembly with respect tothe pedal axle (5) by means of connecting rods (7) with an essentiallygreater length than that of the connecting rods (6) of conventionalbicycles.

The connecting rods (7) by means of which the assembly pedals (4) isestablished with the system of the invention are particularly of alength between 250 and 360 mm, being able to be arranged in an assemblycoupling by themselves with respect to the pedal axle (5) of the drivesystem, or by means of a securing arrangement on conventional connectingrods (6), as a supplement thereof, as depicted in FIG. 4.

This arrangement of the drive system in accordance with the inventionmeans that the user (3) of the bicycle will adopt a posture such that,as shown in FIG. 5, when pedaling in the position of maximum extension,the extended leg forms an angle (α″) of 155° at the knee, whereas anangle (β″) of 145° is formed between said extended leg and the body ofthe user (3).

In addition, as shown in FIG. 6, in the position of maximum bending, thebent leg forms an angle (α″′) of 44° at the knee, whereas an angle (β″′)of 62° is formed between said bent leg and the body of the user (3).

1. Improvements in the drive system of bicycles, of the type in whichthe pedal axle is arranged in a position behind the vertical of the seatof the bicycle, characterized in that the pedal axle (5) is located at adistance between 185-300 mm behind the vertical of the seat (2) and inthat the pedals (4) are incorporated in connecting rods (7) of a lengthbetween 250 and 360 mm.
 2. Improvements in the drive system of bicyclesaccording to claim 1, characterized in that an allowance of the knees ofthe user (3) when pedaling of between a maximum angle (α″) of 155° and aminimum angle (α″′) of 44° is determined between the position of thepedal axle (5) and the length of the connecting rods (7). 3.Improvements in the drive system of bicycles according to claim 1,characterized in that an allowance of the hip of the user (3) whenpedaling of between a maximum angle (β″) of 145° and a minimum angle(β″′) of 62° is determined between the position of the pedal axle (5)and the length of the connecting rods (7).
 4. Improvements in the drivesystem of bicycles according to claim 1, characterized in that theconnecting rods (7) for the assembly of the pedals (4) are secured onconventional connecting rods (6) of a smaller length by means of whichthe assembly to the pedal axle (5) is determined.